This disclosure is directed to devices and methods for imaging of documents and correcting for the distortion that results with image forming devices and documents that tend to be non-planar, such as the centerfolds of open books.
Generally imaging a non-planar document with a centerfold is accomplished by placing the open document face down on the surface of the platen of a xerographic copier or document scanner. Since the document does not lay flat against the platen, the raised portion, with respect to the platen, of the document falls outside of the focal length range for which the image forming device may properly project the image of the document. Therefore, the portion of the document is not clearly imaged, resulting in the copy of the raised portion being compressed and dark causing portions of the copy to be out of focus and/or distorted. Additionally, when copying a non-planar document, such as a book, on an image forming device, the document is pressed down onto the platen of the copying device, which may result in damage to the document.
Attempts have been made in the past to resolve similar problems to those discussed above. U.S. Pat. No. 5,072,252 discloses a bundle of fiber optics the size of a book as an accessory to help prevent damage to the spine while copying the book. However, this accessory is the size of the entire book and does not image the spine. U.S. Pat. No. 5,973,769 discloses a plastic “T” shaped insert to eliminate the shadow that occurs while copying a book. However, this insert does not image the area of the spine but instead reflects the light to prevent the dark area from occurring. U.S. Pat. No. 6,313,954 discloses a corrective tens the size of the book inserted under the book while copying the book.